[SchemaValidationError] 'selection' was unexpected

Hi,

I am following a Google Colab which uses altair for visualization.

I don’t plan to use interactive notebook, so I am using altair-viewer for rendering via Python terminal. Unfortunately, I run into following exception:

    raise SchemaValidationError(self, err)
altair.utils.schemapi.SchemaValidationError: Invalid specification

        altair.vegalite.v4.schema.channels.Color, validating 'additionalProperties'

        Additional properties are not allowed ('selection' was unexpected)

Here is my sample code (same as one found on colab):

import altair as alt

alt.data_transformers.enable('default', max_rows=None)
alt.renderers.enable('altair_viewer')

# Load data (skipped for brevity)

occupation_filter = alt.selection_multi(fields=["occupation"])
occupation_chart = alt.Chart().mark_bar().encode(
        x="count()",
        y=alt.Y("occupation:N"),
        color=alt.condition(
            occupation_filter,
            alt.Color("occupation:N", scale=alt.Scale(scheme='category20')),
            alt.value("lightgray")),
    ).properties(width=300, height=300, selection=occupation_filter)

# Explicitly call show
occupation_chart.show()

I have tried both pip install altair and pip install git+git://github.com/altair-viz/altair.git

Following example from altair doc seems to work fine from terminal:

>>> import altair as alt
>>> 
>>> # load a simple dataset as a pandas DataFrame
... from vega_datasets import data
>>> cars = data.cars()
>>> chart = alt.Chart(cars).mark_point().encode(
...     x='Horsepower',
...     y='Miles_per_Gallon',
...     color='Origin',
... ).interactive()
>>> chart.show()
Displaying chart at http://localhost:21098/

Please guide how to unblock myself. Apologies if this is a noob question, my first time trying altair.

Thank you!!!

[jakevdp]

Does it open up charts at your end?

Does what open up charts? None of your code includes the data, so I cannot run it. Try to create a short, complete snippet, with no reference to data files on your computer, that I can copy and paste into a terminal to see the error you’re seeing.

[jakevdp]

I can’t run your code, because your data does not exist on my system. Can you create a minimal example that reproduces the error?